AP Macroeconomics Formula Sheet 2026 — All Equations & Multipliers
AP Macro does not provide a formula sheet during the exam. Every equation here must be memorized. The good news: there are fewer than 20 equations that actually appear on FRQs, and many of them connect logically once you understand the underlying model.
National Income & GDP
| Formula | Variables | What it calculates |
|---|---|---|
| GDP = C + I + G + (X − M) | C = consumption, I = investment, G = gov't spending, X = exports, M = imports | Expenditure approach to GDP (most tested) |
| GDP = W + R + I + P | W = wages, R = rent, I = interest, P = profit | Income approach (less common on FRQs) |
| Real GDP = Nominal GDP / GDP Deflator × 100 | GDP Deflator = price level index | Adjusting for inflation |
| GDP Deflator = (Nominal GDP / Real GDP) × 100 | Calculating the price level | |
| % Change in Real GDP = (Real GDP₂ − Real GDP₁) / Real GDP₁ × 100 | Economic growth rate |
Key insight: Exports add to GDP; imports subtract. Net exports (X − M) can be negative — this is a trade deficit.
Multipliers
Multipliers are among the most heavily tested quantitative topics on AP Macro FRQs.
| Formula | Variables | When to use |
|---|---|---|
| MPC = ΔC / ΔY | MPC = marginal propensity to consume, ΔC = change in consumption, ΔY = change in income | Finding how much of each extra dollar is spent |
| MPS = 1 − MPC | MPS = marginal propensity to save | MPC + MPS always = 1 |
| Spending Multiplier = 1 / MPS = 1 / (1 − MPC) | Total impact of a change in autonomous spending (G, I, C) | |
| Tax Multiplier = −MPC / MPS | Negative because taxes and GDP move in opposite directions | Impact of a change in taxes on GDP |
| ΔGDP = Spending Multiplier × ΔSpending | Calculating total GDP change from a stimulus | |
| ΔGDP = Tax Multiplier × ΔTax | Calculating total GDP change from a tax change |
The spending multiplier is always 1 larger in absolute value than the tax multiplier. This is why government spending is considered more stimulative than an equal tax cut.
Money & Banking
| Formula | Variables | When to use |
|---|---|---|
| Money Multiplier = 1 / Required Reserve Ratio (RRR) | RRR = reserve requirement (e.g., 0.10 = 10%) | Maximum new money created from a deposit |
| New Money Created = Initial Deposit × Money Multiplier | After a new deposit enters the banking system | |
| New Money Created = Excess Reserves × Money Multiplier | Excess reserves = deposits − required reserves | After open market operations |
| MV = PQ | M = money supply, V = velocity, P = price level, Q = real output | Quantity theory of money (long run) |
Inflation & Price Indices
| Formula | Variables | When to use |
|---|---|---|
| Inflation Rate = (CPI₂ − CPI₁) / CPI₁ × 100 | CPI = Consumer Price Index | Calculating inflation between two periods |
| CPI = (Cost of Basket in Current Year / Cost of Basket in Base Year) × 100 | Constructing a price index | |
| Real Interest Rate = Nominal Rate − Inflation Rate | Fisher equation (approximate) | Adjusting interest rates for inflation |
| Real Wage = Nominal Wage / Price Level | Purchasing power of wages |
Unemployment
| Formula | Variables | When to use |
|---|---|---|
| Unemployment Rate = (Unemployed / Labor Force) × 100 | Labor Force = employed + unemployed (actively seeking) | Calculating the official unemployment rate |
| Labor Force Participation Rate = (Labor Force / Working-Age Population) × 100 | Measuring labor force attachment |
Key concept: Discouraged workers are not counted in the labor force, so when they stop looking for work, the unemployment rate can fall even with no new jobs. This is tested on both MC and FRQ.
International Trade & Exchange Rates
| Formula | Variables | When to use |
|---|---|---|
| Trade Balance = Exports − Imports | Positive = surplus; negative = deficit | Current account balance |
| Current Account + Capital Account = 0 | Balance of payments identity | A CA deficit means a KA surplus |
| % Change in Exchange Rate = (New Rate − Old Rate) / Old Rate × 100 | Currency appreciation/depreciation |
What's NOT a Formula (But Gets Tested Quantitatively)
- Loanable funds market shifts — no formula, but you must show the graph and identify the new interest rate direction
- AD/AS shifts — identify whether SRAS/LRAS/AD shifts and by how much using multipliers
- Open market operations: Fed buys bonds → bank reserves increase → money supply increases → interest rates fall → investment increases → AD shifts right
- Crowding out: Government borrowing increases demand for loanable funds → real interest rate rises → private investment decreases → partially offsets fiscal stimulus
How to Use These Formulas on the FRQ
- Write the formula first — show the equation before plugging in numbers. You earn a point for the correct formula even if arithmetic fails.
- Label every graph — axes, curves, equilibrium point, and the shift. Unlabeled graphs earn no credit.
- Show the chain of reasoning — "Because MPC = 0.75, MPS = 0.25, so the spending multiplier = 1/0.25 = 4, and ΔGDP = 4 × $200B = $800B."
- State direction explicitly — "real interest rates increase," "output falls," "unemployment rises." Vague answers lose points.
Calculate your predicted AP Macro score
AP Macroeconomics Score Calculator →AP Macro Score Cutoffs (2026)
| AP Score | Composite Range |
|---|---|
| 5 | 75–100 |
| 4 | 58–74 |
| 3 | 42–57 |
| 2 | 28–41 |
| 1 | 0–27 |
Frequently Asked Questions
Does AP Macroeconomics provide a formula sheet?
No. AP Macro does not provide any formula sheet during the exam. All equations must be memorized. The multiplier formulas (spending multiplier, tax multiplier, money multiplier) are the most tested calculations on the FRQ section.
What's the most important formula on the AP Macro exam?
The spending multiplier (1/MPS) and tax multiplier (−MPC/MPS) appear on nearly every AP Macro FRQ. Know them cold. The money multiplier (1/RRR) also appears frequently in monetary policy questions.
How many calculation questions are on AP Macro?
The AP Macro FRQ section includes 3 questions; at least 1–2 typically require numerical calculations using the multiplier formulas, inflation rates, or money creation. The multiple choice section includes some calculation questions as well.